Durable Service Life Predication And Analysis Of Reinforced Concrete Based On Two-Dimension Diffusion Of Chloride Ion

The durability of reinforced concrete structure is now a concerned problem researched by the international subject of structural engineering. Because The durability of reinforced concrete is ignored by people in the past years,a lot of reinforced concrete structure which is used only thirty to forty years or even ten to twenty years failed before its normal using years due to durability failure,and it results in huge economic loss and bad social impact.There are many factors which can cause reinforced concrete structure durability destruction,but reinforcement corrosion is the uppermost one.Chloride ion is the principal factor causing reinforcement corroding,therefore it is a matter of great significance to research the durability problem of reinforced concrete structure under the circumstances of chloride ion.Based on the background of 'The Six Group Researching Subject of National Concrete Code Project[GBKY600]' and 'Scientific Research Found of Person with Excellent Ability of Huaqiao University[05BS303]',this paper researched the mechanism of chloride multiple- dimension erosion, the mechanism of chloride ion action on steel bar,and the beginning corrosion time of steel bar. Exact researching contents are as follows:1 , The mechanism of chloride erosion and the mechanism of chloride ion action on steel bar are analyzed.Inner and outer factors having an effect on erosion speed of chloride ion and its impacting law are detailedly introduced,at the same time this paper provided scientific advice for the durability design of reinforced concrete.2, The structural reliability theory and the primary calculation methods of degree of reliability are introduced. Model of degree of reliability of one-dimension diffusion of chloride ion is set up using JC method for the first time;It is found after analyzing and researching that this model is preciser than the model of degree of reliability set up using the center method, and fit the structure which demanded better solving precision for the beginning corrosion time of steel bar.3 , A finite difference model of two-dimension diffusion of chloride ion erosion is set up using unconditionally stable alternating direction implicit scheme for the first time.This model can make sure steps are free and calculation result is absolute convergence,and is used mostly to conculate the beginning corrosion time of steel bar in the corner of rectangle section members whose boundary and initial conditions are complex. After comparative analysis of this model and analytical model,it is found that the calculation precision of this model is high and application range is wide.This model can be applied to practice.